Electron-discharge device



sept. 11, y1923. i 1,467,318

W. J. HERDMAN ELECTRON DISCHARGE DEVICE Filed Aus. 17 192@ 3 Sheet 1 mm N sept. 11, 1923. 1,467,318

` W. J. HERDMAN ELECTRON DISCHARGE DEVICE Filed Aug. 17. 1920 3 Sheets-Sme?l 5 Patented sept. 1,1, 1923."

UNITED STATES WILLIAM J. HERDMAN, 0F TORONTO, ONTARIO, CANADA.

ELECTRON-DISCHARGE DEVICE.

Application iled August 17, 1920. Serial No. 404,065.

To all whom 'it may e011 cern v Be it known that I, WILLIAM J. HEnnMAN, a citizen of the United States of America, and a resident of Toronto, county of York, and Province of Ontario, Canada, have invented a new and useful Improvement in Electron-Discharge Devices, of which the following is a specification. l -My invention relates to electron discharge devices and pertains specifically to that class of such devices which are adapted chiefly to use in radio telegraphy and telephony and manual telephony.

The principal object of my invention comprises, producing a two electrode tube or valve of novel form, in which the internal resistance of the tube or the impedance of the gap between the cathode and anode may be varied toachieve a modulation of the space or thermionic current without necessitating the interposition of a third electrodeor grid between the anode and cathode.

I accomplish thisand other very desirable features that will hereinafter be pointed out and described, by a novel construction of tube and elements therein, whereby the property of magnetostriction is utilized to effect a movement of the anode or plate with respect to the cathode or filament, to thereby decrease or increase the distance between the filament and plate, and'to likewise decrease or increase the effective plate area, to produce an extremely wide variation of the plate current.

Magnetostriction is a phenomenon of ferromagnetic bodies', discovered by Joule in 1842, since which tin-ie experiments have proven that all magnetic` metals and magnetic alloys when magnetized, aresubject to changes in length and volume. Some nickel steels exhibit. the greatest coeiiicient of magnetostrietion, or in other words, the greatest change in length and volume when magnetizedfand these changes are in the nickel 4steels proportional t0 the magnetizing force.

It has been found that steel alloyed with 46% of nickel exhibits when' magnetized, a marked'extension' of length. Steel alloyed 'with 25% of nickel shows practically no increase of length when magnetized, while pure nickel contracts or shortens when magnetized. In carrying out my idea, I employ moving members composed of rods, wires or tubes ofnickel steel. preferably in combination with corresponding rods, wires or tubes 0f nickel or rum-magnetic metal and attach Fig. 1 is a diagrammatic elevationof one i lembodiment of my .ideaand showsalso diagrammatically a clrcuit connection therefor.

Fig. 2 is an enlarged sectional elevation of the plate moving means used in Fig. 1.

Fig. 3 is a sectional plan view of the plate moving means taken-on the line A-A of Fig. 2.

Fig. 4 is a diagrammatic elevation of an alternative form of my idea and shows also diagrammatically a circuit connection therefore.

Fig. 5 is an enlarged plan view' of the tilament. and plate shown in Fig. 4.

Fig. 6 is an enlarged sectional elevation vof the plate moving means shown in Fig. 4.

Fig. 7 is'a sectional plan view of the plate movlng means taken on the line B-B of Fi 6. l

dig. 8 is a diagrammatic elevation of a still further embodiment of my idea, gether with an associated circuit.

Referring no w to the simple. embodiment of my idea shown in Fig. 1, they device comprises an' evacuated glass vessel formed with a spherical central portion 2 and two opposed tubular varms 80 and 90. A fila-g ment 7 is situated centrally with respect to the spherical portion of the tube vand'the plates 5 and 6 are maintained'relatively close to the filament and on opposite sides thereof by means of lthe plate supporting and plate moving members 3 and 4, respectively, theconstructio'n of which Will be described later herein. The ilanient is provided with a battery 14 for heating purline insulated wire are slipped over the arms of the tube containing the moving members 3 and 11 as shown. These coils are as indicated, connected in series, and their free terminals are 'connected with the prima-ry 18 of a transformer, the secondary of which is adapted to be connectedA to the source of in.-

vcoming signals or voice currents. The movposes and coils comprising many turns of ing members 4 and 3 are provided with termlnals as 13 and 12, and these terminals are connected' together bv conductor l1 and to the itive terminal of the plate battery 15, t e negative terminal of which is connected to one terminal of the secondary 16 of a transformer, the remaining terminal of which is connected to `the filament 7. The primary 17 of this transformer is adapted to be connected to any suitablel receiving device or other device for utilizing the modulated current.'

Referring now to Figs. 2 and 3, the plate movin members 3 and 4 before referred to comprise, a series of telescoping tubes of nickel steel and nickel. Tube 32 is of nickel steel and is provided with a supporting cup 3l, having a stem 37 by which the arrangement of tubes' is supported in the gla containing tube. The free extremity of tube 32 is rivetted or otherwise secured to a tube 33 of nickel, which is likewise rivetted or otherwise secured at vits free extremity to a tube 34 of nickel steel within which a further tube 35 of nickel is disposed and secured to the free extremity of tube 34, and within this latter t1 35, a rod 36 of nickel steel is secured as hown. The rod 36 bears rigidly attached at its free extremity, the plate or anode 5. It will be observed that if the coil 8 be energized to magnetize the -moving member 3, that the nickel steel tube 32 will elongate to carry the various ltubes which it encirclcs and consequently, the plate 5 nearer to the filament 7, that the tube 33 of nickel will contract to likewise carry the tubes which it encircles and consequently, the plate 5 nearer to the filament, that the tube 34 of nickel steel will expand to carry its encircled tubes forward, that the tube 35 will contract and the rod 36 will ex and to complete a series of five motions, w ich are cumulative and result in carrying the plate 5 closer to the filament 7. Ex riments have shown that this expansion an contraction is molecular in nature and will follow the finctuations of the current in the coil 8 for extremely high periodicities. When the plate 5 is by this means moved nearer to the filament, obviously, the effective area exposed for the reception of electrons from the lilament by the' plate, is increased, while the impedance of the space gap between the filament and the late is actually reduced due to decreasing t e distance between the plate and the filament, and conversely, as the plate is moved away from the filament, the effec-4 tive area of the plate is reduced and the impedance of the ga is increased. -There is therefore genera in the platev circuit and consequentlyin secondary 16 of the transformer an exact reproduction and further as shown by experiment, an amplification of the current traversing the coils 8 and 9.

Obviously, what has just been said with a half rod 64 of nickel steel.

regard tothe movement of plate 5, is equally true of plate 6, the use of two plates merely increasing the total quantity of plate current.

It will be noted that the plate moving members regarded from the standpoint of ,their thermal expansion, constitute a compound thermostat, the nickel steel members having a coefficient of 8.22X10-, while the nickel members have a coeicient of expansionof 12.8X10-, or an expansion ratio of 2 to 3, Hence, by choosing proper proportioned lengths of the nickel steel and nickel members, the expansion of the various component arts of the movingr members may be so ba anced that changes of temperature can bc entirely compensated and the position of the plates relative to the filament maintain constant, irrespective of temperature changes.

Referring now to Fig. 4, I have shown an alternate embodiment of my idea, comprising an evacuated glass vessel 40, within which is located substantially centrally a `filament 41. The vessel is provided with a tubular extension positioned opposite the filament supporting stem and within this tubular portion there is located and maintained a plate moving member com ed of the two members 48 and l49. hese as shown in Figs. 6 and 7, each consist of a nest of alternate half c linders of nickel and nickel steel. Mem r 48 is adapted to shorten when influenced by magnetism to exhibit the property of magnetostriction, and for that reason the outside half tube 70, to which is attached the support 76, is composed of nickel. The free extremity of the half tube is rivetted or secured to a' half tube 71 of nickel steel, the free extremity of which is rivetted or otherwise secured to a half tube 72 of nickel and the free extremity of this tube is rivetted to a half tube 73 of nickel steel, which in turn, is secured at its free extremity to a half rod 74 of nickel. The member 49 is adapted to expand when magnetized, and for this reason, the outside tube 60 attached to the supporting member 75 is of nickel steel, the free extremity of which is secured to a half tube 6l of nickel and the free extremity of this latter tube is secured to a halfl tube (i2-of nickel steel, whichencloses and is attached4 at its free extremity to a half tllbe 63 of nickel. This latter tube cncloses and supports at its free extremity The bars 64 and 74 are pivoted attheir free extremities in a support or arm 75 as shown in Fig. 4, which carries a plate 50, and as shown in Fig. 5, this plate is positioned-normally in a plane parallel to that occupied by the longitudinal axis of the filament 41. The members 48 and 49 are encircled as shown b a magnetizin coil 51, the terminals of which are connecte to the secondary 52-of a transexpansion of i lll lll

former,the primary of which is adapted toA be connected to any source of incoming signals or speech currents. The terminals -46 and 47 of the plate moving members 48 and bers 48 and 49 will be influenced to exhibit the property of magnetostriction and as the degree of magnetization increases, member 48 will contract and member 49 will expand to rotate the arm 75 and move the plate 50 nearer to the filament 41, to decrease the impedance of the gap between plate and filament as hitherto described,A Further, as the degree of magnetization decreases, member 48 will expand and member 49 will contract to move the plate 50 away from the filamentto increase the impedance ofthe gap. It will lbe noted that regarded from the standpoint of their thermal expansions, members 48 and 49 constitute compound thermostats and consequently, as has hitherto been explained herein, they obviously may be sol constructed that the position of the p ate relative to the filament may be maintained constant irre l spective of temperature changes.

vReferring now to Fig. 8, in which I'have illustrated a still further embodiment of my idea, the evacuated glass vessel 100 is provided with a filament 101 and a tubular extension positioned opposite the filament supporting stem. The tubular extension serves to enclose and support a plate moving member l03,-.which in this instance, is composed of two flat members 114 and'115,'one of nickel steel and vthe other of nickel, which are rivetted or welded together in the form of a bi-metallic thermostat, one extremity of this member is rigidly maintained in the s tubular extension of-the tube 100 and the free extremity of the member bears rigidly attached a plate 102.I Obviously, when this member is magnetized, the nickel steel portion thereof, 114 tends to expand, while the nickel portion thereof, 115 tends to contract to cause thel member to bend or flex, result-l ing in carrying the plate 102 nearer the filament 101, to modify the impedance .of the a between the filament and the plate as it erto described. The filament is adapted to be heated by the battery 108 and the moving member and plate are connected tothe positive terminal of a plate battery 108, the negative terminal of which vis connected to one terminal of the Secondary 110 of a transfilament.

former, the remaining. terminal of which is connected to the filament 101. The primary of this transformer 111 is adapted to be connected to any suitable receivlng device. vA permanent'ma neti'zing coil 105 encircles the tubular extension of the tube 100 and consel quently, the plate moving member 103 andl is connected in series with an adjustable resistance and fa batteryv 107 .v A, further coil 104 encircles the primary 112 of which ,is adapted to be connected to any source of in.v

coming signals or speech currents. It will be observed that by means of the .permanent magnetizing coil 105,1 may selectively position the Vplate member 102 with respect-to the filament 101,""and through this means.

obtain some measure of control over 'the impedance of the VVhle I have illustrated and described` gap between the plate andv methods of moving the plate relative' to the v filament it is obvious` that these Esame methods or others similar could be used to move the filament relatively to the plate, to achieve thesame results.

` It will be lobserved from the foregoing, that my lnovel valverequires no third electrode or grid to achieve modulation of the space or plate current, and that further, I am enabled to accomplish in a novel way, a very substantial variation or modulation of the space current by means of but two electrodes.

While I have thus illustrated andIdeJ scribed several embodiments or forms of my device, I wish it to be clearly understood that I may vary thel details thereof without departing from the spirit or narrowing the scope of my invention. v Having thus completely described and dis- .closed m device,.what I desire to secure by United tates Letters Patent' is as follows:

1. In an electron discharge device, an.

evacuated vessel, an electron emitting mem- .ber therein,an velectron receptive member adjacent to said emitting member, and mag-- netostrictional means for movin said recep tive member 4relatively tovpsaidemitting member. Y, l

2. In an electron discharge device,` an evacuated vessel, an electron emitting member therein, an'electron v rece tive l:member adjacent to said emitting mem r, andmaggnetostrictional means for moving said reeepi f tive member relatively tov saidf-emittin member from without vsaid ev'acuatedivesse i.

` 3. In an electron discharge device, an

evacuated vessel, a cathode therein, an anode adjacent tofsaid cathode, and' magnetostrictional means for modifying the impedance of the gap separating said anode and said l cathode.

4. In an electron dischar e device, an

evacuated vessel, a `cathode t erein, a plu-- .ality of anodes adjacent tov said cathode,

and magnetostrictional means for moving said anodes to modify the impedanceof the gap between said anodes and said cathode.

5. In an electron. discharge device, an evacuated vessel, a cathode therein, anodes therein, and magnetostrictional means for varying the distance between said cathode and said anodes.

6. An electron discharge tube, comprising an evacuated vessel, a cathode therein, anodes positioned opposite said cathode, and magnetostrictional means for modulating the impedance of the gap between said cathode and said anodes, from Without said vessel.

7 In an electron discharge device, a cathode, an anode adjacent to said cathode and magnetostrictional means for modifying the impedance of the gap separating said anode and said cathode.

8. In an electron discharge device, i a. cathode, anodes and magnetostrictional means for varying the distance between said cathode and said anodes. I

9. In an electron discharge device, a conl5 tainer, cathodes and anodes therein, and magnetostrictional means for varying the relative relation between said anodes and said cathodes.

WILLIAM J. HERDMANL `Witnesses:

R. H. DOUGHERTY, J. S. LIGHTBOUND. 

